1. Field of the Invention
Embodiments of the present invention generally relate to a display device, and more particularly, to a display device for artificially controlling biorhythm.
2. Description of the Related Art
Recently, a technique for controlling biorhythm by artificially controlling light environment has been developed [Oliver Stefani et al. “Evaluation of Human Reactions on Displays with LED Backlight and a Technical Concept of a Circadian Effective Display” SID 2010 Digest 75.4 (2010)].
Specifically, a living body has a clock mechanism (circadian clock) in the body, and controls periodic phenomena of vital functions. The representative phenomena are rhythm of sleeping/awakening, change in body temperature or blood pressure, etc. These phenomena are controlled by biorhythm.
Particularly, it has been studied that a hormone called melatonin is involved in controlling the rhythm of sleeping/awakening, and it has been found that the rhythm is controlled by change in the amount of melatonin secreted. And the change in the amount of melatonin secreted depends on light environment.
That is, the amount of melatonin secreted increases in a dark environment, and thus the sedative property of melatonin is exhibited. On the contrary, the amount of melatonin secreted decreases in a bright environment, and thus the awakening property of melatonin is exhibited.
This has been already studied, and an illumination device or display device with a melatonin control effect, to which the technique is applied, has been released in the market.